ctjmmings



2 Sheets-Sheet 1'.

(No Model.)

' `l Y UI.. CMMINGS.e

-PURNAGR Patente@ Deo. l11.11883. j ,2f/(91.

(No Model.)

, Y 2 shets-sneet 2. U. CUMMIN GS.

' FURNAGE.

Patented'ne. 1.1, 1883.

-ZZWJ UNITED STATESY PATENT .OFFICE... l

Ulmen cnMMiNes, oF BUFFALO, New vonk.

FURNACa SPECIFICATION forming part of Letters Patent No. 289,990,datedvDecember 11, 18.83.

, Application filed February 23, 1883', (No model.)

To all whom it may concern:

kBe it known that I, Unika OUMMINGS, of the city of Buffalo, in thecounty of Erie and State of New York, have invented new and usefulImprovements in Furnaces, of which the following is a specification.

This invention relates to an improvement in boiler and other furnaces,whereby the combustion of the fuel is rendered more perfect and theformation of smoke is to a large eX- tent prevented.

It is well known that in furnaces constructed in the ordinary mannerlarge volumes of combustible gases arev developed, which escape withoutbeing consumed, and which not only involve a heavy loss of fuel, butalso materially increase the volumes of smoke which are produced by thefurnace. It is also well known that these combustible gases can beconsumed and the combustion rendered more perfect by admitting fresh airto the furnace at a point where it can be combined with these combustible gases, and that the desired result is most perfectly attained whenhot airis so admitted to the furnace, because chilling effects, due tothe admission of large volumes of cold air to the furnace above thegrate, are thereby avoided.

The object of my invention is the construction of a simple and cheapdevice whereby the heated air can be commingled with the combustiblegases generated by the burning fuel on the grate, such device being soconstructed that it can be readily applied to furnaces of ordinaryconstruction already in existence; and my invention consists, to thatend, of the peculiar construction of the device, which will behereinafter fully set forth, and pointed out in the claim.

In the accompanying drawings, consisting of two sheets, Figure 1represents a longitudinal section of ya furnace provided with myimprovements. Fig. 2 is a cross-section of the same. Fig. 3 is alongitudinal Section, on an enlarged scale, of the air-heatingcontrivance arranged below the grate. Fig. 4 is a fragmentary top planview ofthe same. Fig. 5 is a cross-section of the frame 'of theair-heating contrivance. Fig. 6 is a longitudinal section, on anenlarged scale, of one of the adjustingj plates'of the same. Fig. 7 is aperspective Like letters of reference refer to like parts in the severalfigures. l

A represents the grate of a steam-boiler or other furnace; B, thecombustionchamber above the grate; b, the fire-door; b', the bridgewall;C, the ash-pit, and c the ash-pit door, all of any suitable andwell-known construction.

The air-heating contrvance arranged below the grate in the ash-pit C iscomposed of a series of metallic plates or slats,` D, which are arrangedin such close proximity to the grate that the heat which is radiateddownwardly by the burning fuel on the grate is partly absorbed andpartly reflected by the plates D, and imparted by the latter to the airwhich enters from the ash-pit into the space between thegrate and theplates D. The plates D are constructed with journals d', which rest innotches e, formed in side bars,'E, of a frame which is arranged in theash-pit, and which supports Vthe plates D. The frame E is supported bystandards or legs f, and secured in place by set-screws f. The plates Dextendas far as practicable across the entire width of the ash-pit, soas to prevent as much as possible the air from entering the spacebetween the plates D and the grate, except through the opening at thefront end of the furnace. The plates D are connected by suitable hooks,g, with allongitudinal bar, h, whereby all the plates can be turnedsimultaneously on their journals, thereby enabling the plates to beplaced with their iiat sides toward the grate, as represented in Fig. l,or with their edges toward the grate, as represented by dotted 90 linesin Fig. 3.

I represents an air-heating chamber arranged upon the grate against thebridge-wall b', and open at its lower end, so that a portion yof the airpassing upwardly between the grate-bars enters the chamber I. vThelatter is provided at its top with perforations or slots Z, lthroughwhich the air passes from the chamber I into the flame-space of thefurnace.

The chamber I is constructed of cast-iron or other suitable material,and its front side,

ICO

against which the fuel rests, is protected by a Covering, j, offire-brick or other refractory material.

\Vhen the furnace is in operation, the cold air passes from the ash-pitC into the space between the plates D and the grate A, and a portion ofthe air passes upwardly through the space between the gratebars in frontof the hot-air chamber I, while the remaining portion of the air, afterhaving passed through the space between the grate A and the plates D,passes into the chamber I. The plates D become highly heated by the heatwhich is radiated downwardly by the burning fuel on the grate, and theair in passing over the plates D becomes highly heated before it passesupwardly between the grate-bars and into the eombustioachamber. The airwhich enters the hot-air chamber I has passed over the entire series ofplates D,and has thereby become highly heated, and this air is furtherheated by contact with thc hot walls of the chamber I, so that the airwhich issues into the flamespaee through the openings Z is heated tosuch a degree that it is in the best possible condition to combine withthe combustible gases generated by thc fuel. This hot air combinesreadily with the combustible gases and completes the combustion thereof,thereby insuring a perfect combustion and a correspondingly high degreeof heat, and preventing the formation of smoke. rl`he air which issupplied to the grate and to the namespace of the furnace is by thismeans heated by that portion of the radiated heat which is wasted inordinary furnaces, and the heat which is required for raisingthetemperature of the air does not therefore reduce the temperature of thefurnace. \Vhen a layer of ashes has aecumulated on the plates D whichwould interfere with the operation of heating the air by contact withthese plates, the latter are turned on their pivots so as to assume theposition represented by dotted lines in Fig. 3, whereby the ashes aredumped into the ashpit, when the plates are returned to their formerposition.

If desired, a stationary plate or plates may be substituted for themovable plates D; but I prefer to employ the movable plates,because astationary plate or plates would necessitate the raking out of theashes, which I desire to avoid.

rIhc air-heating eontrivance arranged below the grate and thcair-heating chamber arranged above the grate are both very simple inconstruction, and can be readily applied to furnaces of ordinaryconstruction without nccessitating alterations in the furnace.

I claim as my invention- The combination, with a furnace-grate, A, andash-pit C, ot' pivotcd ai r-hcating plates arranged below the grate andabove the bottom of the ashfpit, with an opening for admitting the airinto the space above the air-heating plates, and mechanism,substantially as described, whereby the pivotcd plates can besimultaneously turned on their pivots for discharging the ashes,substantially as set forth.

URIAII CUMMINGS.

\\"itnesscs:

JNO. J`. BoNNnn, (liras. F. Gnvna.

